Luminescence properties of Ln3+ doped BaMoO4 (Ln3+ = Sm3+ and Dy3+) phosphors under UV excitation

Ln3+ doped BaMoO4 (Ln 3+ = Sm3+ and Dy3+) nanoparticles have been synthesized successfully using ethylene glycol as a solvent. All the prepared samples are well indexed into the pure scheelite-type tetragonal structure of BaMoO4, the doping of trivalent ions (Ln3+) in to the bivalent host ions (Ba2+) sites of the BaMoO4 do not change the pure tetragonal structure of BaMoO4 although there is a charge difference between Ba2+ and Ln3+. The SEM image of the prepared BaMoO4 samples shows a number of uniform shuttle-like nanocrystalline with protrusion in the middle. The doping of Ln3+ ions do not change the morphology of the BaMoO4. The photoluminescence study has been carried in detail by measuring the excitation and emission spectra of the prepared samples. The excitation spectrum consists of a broad band with a maximum at about 268 nm thereby demonstrating the transfer of energy from MoO2-4 groups to the doped Ln3+ ions. Yellow emission is dominated over blue in case of Dy3+ doped BaMoO4 and in Sm3+ doped BaMoO4 red emission dominated over other lights under UV excitation. The luminescence intensity is highest at 10 at.% Ln3+ under the UV excitation. Under this UV excitation BaMoO4:Sm3+ exhibits strong orange-red and BaMoO4:Dy3+ greenish-yellow emissions. Excitation of Dy3+ in thin film of BaMoO4 emits an intense yellow color which could be applicable in the field of biological assays and biological fluorescence labeling.